Positorq Oil Shear Absorber Brakes

Designed For Tension Control, Dynamometer Load Brakes, Drawworks Brakes

Positorq Tension Brakes

  • Steel strip, paper, wire
  • 50 Lb. Ft. to 180,000 Lb. Ft. Continuous tension
  • Up to 3000 Thermal HP.
  • Linear control based on pressure
  • Quick Response – Smooth Quiet Operation
  • Dynamic Stopping Capability for Set or E-Stop

Positorq Dynamometer Load Brakes

  • Low Speed High Torque Load Testing
  • Final drive, transmissions, axles
  • Direct connect to test item – no speed up drive
  • 50 Lb. Ft. to 180,000 Lb. Ft. continuous tension
  • Up to 3000 Thermal HP.
  • Linear control based on pressure
  • Quick Response – Smooth Quiet Operation

Winch/Drawworks Tension Brakes

  • Up to 300,000 Lb. Ft. Static Torque
  • Up to 3000 Thermal HP.
  • Linear control based on actuation pressure
  • Quick Response – Smooth Quiet Operation
  • Totally enclosed sealed – Impervious to moisture and salt water
  • Marine duty with biodegradable fluid
Positorq Oil Shear Tension Brake

The Positorq Oil Shear Absorber brakes are a unique design for continuous tension control, high torque low speed dynamometer load brake applications, and large mooring winch or drawworks brakes. The unique Oil Shear Technology provides extremely smooth, ultra quick response, negligible wear with no adjustment required, high energy dissipation in a compact package, and noise free. Positorq Brakes are rated up to 180,000 Lb. Ft. Slip Torque and 3000 Thermal Horsepower.

The Positorq Brakes operate by applying pressure on a piston or pistons clamping the friction stack. The tighter the clamping force the higher the torque, and it is not affected by speed. The actuation medium can be pneumatic or hydraulic. The hydraulic actuation is more controllable.

Transmission fluid in the brake transmits torque between the friction disc and drive plates providing the torque. As this fluid is heated it is pumped back through a Forced Lube Cooling Unit that has oil-to-water or oil-to-air cooling, filters, pumps and reservoir. The FLCU allows the brake to be very compact, with low inertia.

Shaftless Unwind Stand Shaftless
Unwind Stand
Steel Unwind Stand Steel
Unwind Stand
Paper Unwind Stand Paper
Unwind Stand
Plastic Unwind Stand Plastic
Unwind Stand
Axle Dyno Load Brake Axle Dyno
Load Brake

Forced Lube Cooling Unit

The secret behind the Positorq Tension/Dyno brakes is the Forced Lube Cooling Unit. It consists of a fluid reservoir with fluid flow pumps, actuation pump (if hydraulic actuation), filters, and cooling heat exchangers. Oil-To-Air or Oil-To-Water exchangers can be furnished.

By cooling and filtering the fluid separate from the brake high horsepower thermal loads can be dissipated without over sizing the brake.

FLCU are typically designed for the application to operate one brake or multiple brakes. Various level of controls is available.

Positorq brake applications typically include two major components – the brake connected to the load and a Forced Lube Cooling Unit. The brake is a multiple disc hydroviscous brake featuring Oil Shear Technology developed and refined by Force Control Industries, Inc. starting in 1969. The multiple disc brake stack is actuated by applying a clamping pressure to the stack through a piston. The actuation medium can be pneumatic or hydraulic, hydraulic being more controllable with quicker response. Changing the actuation pressure changes the torque transmitted proportionally.

Because this is a compact design with low inertia rotating components there is little surface area to dissipate thermal energy from the continuous slip load. For that reason we utilize a separate free standing forced lube cooling unit to pump transmission fluid through the brake returning it to be cooled and filtered and returned to the brake.

There are many variations of forced lube cooling units however the basic requirements include the following:


Main Fluid Pump

Typically a positive displacement screw pump. This provides positive fluid flow under all conditions, and operates quietly with maximum life expectancy. Small gear pumps are used on some of the smaller systems but can be noisy.

Heat Exchangers

Used to remove the heat from the fluid. Typically either oil-to-air or oil-to-water are utilized. Oil-to-water is most efficient however requires large quantities or water, or local cooling tower.

Oil-to-air is becoming most common today as it is environmentally friendly, requires no water or coolant additives, and is readily available. The downside is on particularly high thermal systems they can become quite large and noisy.


Used to clean the fluid of carbon particles produced by heating the fluid, and impurities getting into the system. Commonly used are screw on filters for quick change out and low cost. Strainers are also included in the tank to catch larger particles.

Pressure Switch

Used to monitor the fluid pressure going into the brake. It is typically wired to the prime mover to stop the operation with a loss of pressure meaning fluid is not flowing to the brake.

Over Temperature Switch

Usually wired into an alarm system or light to warn of fluid temperature exceeding operating levels.

Fluid Reservoir

Used to hold the transmission fluid long enough to settle any sediment, and allow aeration to dissipate.

Kidney Filtration System

This is an external filtering system that includes a small pump and motor continuously circulating a portion of the fluid through a filter system. This allows use of smaller filters on very large systems. In addition it is used for draining and re filling the reservoir were a complete fluid change needed. New fluid put into the reservoir if filtered assuring clean fluid in the brake system.

Actuation System

When hydraulic actuation is used for the brakes the actuation pump can be located on the reservoir of the forced lube cooling unit using the same fluid.

Multiple Brakes on One Cooling Unit

When operating more than one brake from a single reservoir it is critical that a separate cooling fluid pump system be used for each brake.

Internal fluid heaters

Sometimes it is necessary to heat the fluid before operating. The fluid should be near 100 degrees F for best operation.